im converting one of my 125 gallon tanks to run African cichlids I plan on mixing crushed coral into my sand substrate to get the ph up to were they like it was wounding if it was ok to just use basic aquarium salt in tank also are there any africans that I should keep away from that are highly aggressive thanks

Crushed coral is good for rift lake cichlids as you mention. Even an entire substrate of the coral will work well. It will also add calcium, though not magnesium, but plain Epsom Salt is good for that [more on this below].

I would not use regular salt (aquarium salt, marine salt, whatever) as that is a totally different thing from the so-called "mineral salts" in the rift lakes. You can buy rift lake "salts" but over time that may be expensive. And calcium and magnesium will increase the hardness fine.

Epsom Salt is magnesium sulfate, and as long as it has nothing else in it, works well in aquaria. It doesn't take much, and it is quite inexpensive to buy in drug stores, etc. Of course, you may have sufficiently hard water from your tap without this. But if not, the magnesium will work with the calcium to provide suitable hard water.

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian.[unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]

You can make up your own rift lake mix using bicarbonate soda, Epsom salt and non-iodized salt. I can't remember the exact recipe off hand - and it's a while since I made mine up.

Use coral sand rather than crushed coral - most rift lake cichlids like to dig and the crushed coral will hurt them because it's sharp.

As far as species, you have to decide what lake you like - Malawi, Victoria or Tanganika. It isn't a good idea to try and mix the different lakes. Although, it is possible to mix some Victorians with malawians. Confused yet?

okay thanks guys I differently plan on buy a frontosa I have the substrate figured out but back to the drawing board on salt my lfs guy told me I could just use basic aquarium salt ??? I also plan on leaving my syno cat and my big gibby pleco from my previous south american setup was told they would be fine with higher ph

You'll need more than just aquarium salt - if your ph is already good, use Epsom salt as well.

The syno will definitely be ok - acclimatize him really slowly though since he's been in a SA tank. Putting the gibby in is possible, but puts ALL fish in the tank at the limit of their natural tolerance - gibby on the high end, Africans on the low end. Personally, I wouldn't do it. The gibby would be the onto suffer most with the salts.

I still do not recomend aquarium salt for any freshwater fish. "Salts" as in rift lakes is a very different thing, minerals.

Here's some info on what salt does to fish, copied from my response to this issue a while back:

Salt is detrimental to freshwater fish and plants in varying degrees. To understand why, we must understand what salt does in water.

Salt makes the water more dense than the same water without salt. The aquarium contains water. The bodies of fish and plant leaves also contain water [just as we do--we are, what is it, 70-some percent water?]. The water in the aquarium and the water in the fish/plant are separated by a semi-permeable layer which is the cell. Water can pass through this cell. When either body of water is more dense, the other less-dense body of water will pass through the membrane to equalize the water on both sides.

Water is constantly passing through the cells of fish by osmosis in an attempt to equate the water inside the fish (which is more dense) with the water in the aquarium. Put another way, the aquarium water is diluting the fish's body water until they are equal. Freshwater fish regularly excrete this water through respiration and urination. This is the issue behind pH differences as well as salt and other substances. It increases the fish's work--the kidney is used in the case of salt--which also increases the fish's stress in order to maintain their internal stability. Also, the fish tends to produce more mucus especially in the gills; the reason now seems to be due to the irritant property of salt--the fish is trying to get away from it.

I have an interesting measurement for fish. Dr. Stanley Weitzman, who is Emeritus Research Scientist at the Department of Ichthyology of the Smithsonian Institute in Washington and an acknowledged authority on characoid fishes, writes that 100 ppm of salt is the maximum for characins, and there are several species that show considerable stress leading to death at 60 ppm. 100 ppm is equal to .38 of one gram of salt per gallon of water. One level teaspoon holds six grams of salt, so 1 tsp of salt per gallon equates to more than 15 times the tolerable amount. Livebearers have a higher tolerance (mollies sometimes exist in brackish water) so the salt may be safe for them.

Plants: when salt is added to the aquarium water, the water inside the plant cells is less dense so it escapes through the cells. The result is that the plant literally dries out, and will wilt. I've so far been unable to find a measurement of how much salt will be detrimental to plants; all authorities I have found do note that some species are more sensitive than others, and all recommend no salt in planted aquaria.

The aquarist is one who must learn the ways of the biologist, the chemist, and the veterinarian.[unknown source]

Something we all need to remember: The fish you've acquired was quite happy not being owned by you, minding its own business. If you’re going to take it under your wing then you’re responsible for it. Every aspect of its life is under your control, from water quality and temperature to swimming space. [Nathan Hill in PFK]